Sequential timer having a plurality of predetermined advancement intervals



p 1967 L. BURRAGATO ETAL 3,342,957

SEQUENTIAL TIMER HAVING A PLURALITY OF PREDETERMINED ADVANCEMENT INTERVALS Filed Jan. 5, 1966 5 Sheets-Sheet 1 INVENTORS LUIGI BURRAGATO JOSEPH E. WISER BY ATTORNEY p 1967 L. BURRAGATO ETAL. 3,342,957

SEQUENTIAL TIMER HAVING A PLURALITY OF PREDETERMINED ADVANCEMENT INTERVALS Filed Jan. 5, 1966 I5 Sheets-Sheet 2 FIE. 5

FIG.

INVENTORS LUIG! BURRAGATO JOSEPH E.WISER ATTORNEY Sept. 19, 1967 BURRAGATO ETAL 3,34

SEQUENTIAL TIMER HAVING A PLURALITY OF PREDETERMINED ADVANCEMENT INTERVALS Filed Jan. 5, 1966 5 Sheets-Sheet 3 INVENTORS LU IGI BURRAGATO JOSEPH E.WlSE R ATTO R N EY United States Patent 3,342,957 SEQUENTIAL TIMER HAVING A PLURALITY 0F PREDETERMINED ADVANCEMENT INTERVALS Luigi Burragato and Joseph E. Wiser, Indianapolis, Ind., assignors to P. R. Mallory & Co. Inc., Indianapolis, Ind., a corporation of Delaware Filed Jan. 3, 1966, Ser. No. 518,411 7 Claims. (Cl. 200-38) The present invention relates to timers and more particularly to the means and methods for providing a timer having a selective time interval between step-advances and a rapid advance feature.

Most timers of the type having a plurality of control cams mounted on a camshaft so as to be rotated thereby are step-advanced through the programmed timing cycle. The step-advance is characterized by a high speed advancement of the control cams for a precise angular amount after a predetermined time interval. In most cases, the amount of advance, the rate of advance, and the time interval are determined by a mechanical escapement mechanism. A motor drives the escapement mechanism to store energy in the escapement spring. After a predetermined amount of rotation of the escapement mechanism, the energy in the spring is released to rapidly advance the camshaft carrying the control cams.

One disadvantage of an escapement mechanism such as described above is that the time interval for advancing the control cams is fixed and cannot be easily changed. In order to overcome the aforementioned disadvantage, a few general approaches have been offered. These approaches will be discussed in the following paragraphs.

One approach has been to use an electronic escapement to intermittently energize a drive motor. An electronic escapement uses a variable relaxation-oscillator timing circuit to fire a silicon controlled rectifier in series with the drive motor. The problem with an electronic escapement is that the cost of the components is usually prohibitive as compared to mechanical escapements.

Another approach has been to use two motors, one motor for driving a cam-operated switch for determining the time interval and a second motor for rotating the control cams of the timer. The second motor is usually energized for a precise period of time by the cam-operated switch driven by the first motor. The selective time interval feature is obtained by having more than one cam-op erated switch driven by the first motor and a means for selectively interconnecting the switches. A problem with the latter approach is that two motors are required for the timer. Also, the cam-operated switch driven by the first motor must be returned back to the starting position each time the timer is advanced. This requirement necessitates theuse of a bidirectional cam-operated switch with all the problems attendant thereto.

There is presented in this specification a timer having a single drive means, a first cam means for determining I various time intervals for advancing the timer, and a second cam means for determining the amount of angular advance of the control cams of the timer. The first cam means is coupled to and driven by the drive means. The second cam means is coupled to and driven by the drive means when the first cam means has operated a selected pair of electrical cont-act members. There is a coupling between the first and second cam means so that the first cam means can be driven by the second cam means when it is rotated. The coupling includes a one-way clutch because the second cam means is rotated at a faster rate than the first cam means.

The second cam means of the present invention will always start and stop at a given spot. This feature is obtained by having a solenoid operated clutch for coupling the second cam means to the driving means after a predetermined time interval established by the first cam means. The solenoid clutch is maintained in an energized mode by a pair of contact members associated with the second cam means. Since the second cam means rotates the first cam means, both cam means will stop when the second cam means opens the contact members associated therewith. Both the first cam means and second cam means rotate in one and the same direction. The first cam means rotates at a relatively slow rate until the time interval is established, then the second cam means rotates and drives the first cam means to a starting position. Hence, the second cam means is always rotated one revolution. The first cam means is rotated relatively slow through a portion of a revolution and then at a rapid rate with the second cam means for the balance of the revolution. There is a means for coupling the second cam means to the camshaft of the timer so as to advance said camshaft when said second cam means is rotated.

Since the first and second cam means of the present invention are unidirectional cam means, i.e., they do not have to be returned by a spring to a zero position, the contact members associated with said cam means can be made rapidly by dropping one contact onto another one. The rapid opening and closing of contacts is required for ideal operation of the solenoid clutch.

Another advantage of the timer of the present invention is that the contact members associated with the aforementioned second cam means can be shorted together to continually and rapidly drive the control cams of the timer. Hence a rapid advance can be easily obtained.

Other features of the timer of the present invention will become apparent as this specification progresses.

It is an object of the present invention, therefore, to provide a timer having a step-advance feature with selective time intervals and a rapid advance feature.

It is another object of the present invention to provide a timer having a single driving means for the stepadvance feature and the rapid advance feature, said drive means also being the means for rotating the means for establishing the time intervals for the step-advance feature.

It is a further object of the present invention to provide a timer having a first cam means for determining the time interval for step-advancing said timer and a second cam means for determining the amount of angular advance of the control cams of said timer, said first and said second cam means being driven by a single driving means.

The present invention, in another of its aspects, relates to novel features of the instrumentalities described herein for teaching the principal object of the invention and to the novel principles employed in the instrumentalities whether or not these features and principles may be used in the said object and/ or in the said field.

Other objects of the invention and the nature thereof will become apparent from the following description considered in conjunction with the accompanying drawings and wherein like reference numbers describe elements of similar function therein and wherein the scope of the invention is determined rather from the dependent claims.

For illustrative purposes, the invention will be described in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view of the timer of the present invention.

FIGURE 2 is a diagram showing the cooperation of the various transmission elements of the timer of the present invention.

FIGURE 3 is a sectional view 33 taken from FIG- URE 4 showing the meshing of the various gears in the transmission of the timer of the present invention.

FIGURE 4 is a fragmentary side view of the timer of the present invention showing the physical arrangement of the various transmission elements, the drive motor, and the control cams.

FIGURE 5 is a view illustrating a first phase of the operation of the step-control cam and time base unit cam of the timer of the present invention.

FIGURE 6 is a view illustrating a second phase of the operation of the step-control cam and the time base unit cam of the timer of the present invention.

FIGURE 7 is a view illustrating a third phase of the operation of the step-control cam and the time base unit cam of the timer of the present invention.

Generally speaking, the present invention is a timer of the type having a plurality of control cams mounted on a camshaft so as to be rotated thereby and a plurality of control switches operated by said control cams, said timer comprising: a drive means; first cam means for determining a time interval for advancing said control cams, said first cam means having a plurality of rise and fall contours for operating a plurality of contact members; second cam means for establishing the amount of advancement of said control cams, said second cam means having a contour for opening and closing an associated pair of contact members as said second cam means is rotated; means for coupling said first cam means to said driving means; electrically operated means for coupling said second cam means to said driving means when said first cam means has rotated a predetermined amount; means for coupling said first cam means to said second cam means so as to advance said first cam means with said second cam means; first circuit means for selectively connecting said contact members associated with said first cam means to said electrically operated means, thereby energizing said electrically operated means after a predetermined time interval; second circuit means for connecting said contact members associated With said second cam means to said electrically operated means, thereby deenergizing said electrically operated means after said control cams have advanced a predetermined amount; and a means for coupling said second cam means to said camshaft when said second cam means is rotated.

A more specific embodiment of the present invention is a timer of the type having a plurality of control cams mounted on a camshaft so as to be rotated thereby and a plurality of control switches operated by said control cams, said timer comprising: a drive means; first cam means for determining a time interval for advancing said control cams, said first cam means having a plurality of rise and fall contours for operating a plurality of contact members; second cam means for establishing the amount of advancement of said control cams, said second cam means having a contour for opening and closing an associated pair of contact members as said cam means is rotated; means for coupling said first cam means to said driving means, said coupling means including a first oneway clutch; means for coupling said second cam means to said driving means when said first cam means has rotated a predetermined amount, said coupling means including a solenoid operated clutch; means for coupling said first cam means to said second cam means so as to advance said first cam means with said second cam means, said coupling means including a second one-way clutch; first circuit means for selectively connecting said contact members associated with said first cam means to said solenoid operated clutch, thereby energizing said clutch after a predetermined time interval; second circuit means for connecting said contact members associated with said second cam means to said solenoid operated clutch so as to deenergize said clutch after said control cams have advanced a predetermined amount; and means for coupling said second cam means to said camshaft so as to rotate said camshaft when said second cam means is rotated.

Referring now to the drawing, and particularly to the step-control gear 44. The step-control cam 54 rotates perspective view of FIGURE 1, the component parts of the present invention can be visualized in conjunction with the following description.

The metallic plates 10 and 12 are main structural members of the timer. The terminal block 11 is held between the plates 10 and 12 and is the carrier for the wire spring contact members 17, 18, 19, 20, 21, 22, 23 and 24. The contact members 21 through 24 are shorted together by the member 25. The driving means, hereinafter referred to as the motor 13, and the solenoid 14 are mounted on the plate 12. The solenoid 14 operates the clutch 16 by pulling down on the clutch arm 15. The clutch arm 15 is held to the plate 10 at the point 15'. Also shown in FIGURE 1 is a portion of the first cam means, hereinafter referred to as the time base unit cam 26, for the timer and a portion of the control cams 27 of the timer and a portion of the terminal members 28 associated with said control cams 27.

Referring now to FIGURE 2, the cooperation of the various transmission elements can be discussed.

The motor 13 output shaft has a pinion gear 32 for imparting motion to the balance of the transmission elements in the timer. The motor pinion gear 32 drives the first gear reduction stage 33. The first gear reduction stage drives the reset mechanism gear 34 and the second gear reduction 36. The reset mechanism gear 34 drives through the clutch 16 when the clutch is closed by the energization of the solenoid 14. The pinion gear 35, rotating with the clutch 16, drives the step-control gear 44. The step-control pinion 45 drives the idler gear and pinion 46 which drives the camshaft gear 47. The control cams 27 of the timer are mounted on the camshaft so as to be rotated with the camshaft gear 47.

The first gear reduction stage 33 also drives the second gear reduction stage 36 which, in turn, drives the third gear reduction stage 37. The thrid gear reduction stage 37 drives the intermediate gear and pinion 38 which, in turn, drives the time base unit gear 39 and the subinterval gear 49. The subinterval gear 49 drives the subinterval cams 50.

The time base unit gear 39 drives through the oneway clutch 40 to rotate the time base unit cam 26. When the solenoid 14 is energized, the step-control gear 44 drives the time base unit cam 26 through the one-way clutch 43. When the time-base unit cam 26 is being driven by the step-control gear 44, the one-way clutch 40, which can be a simple pawl for driving a ratchet wheel, is overridden.

Referring now to FIGURE 3, a view showing the various gears, clutches, ratchets, and cams of the present invention can be discussed.

The motor pinion 32 drives the gear reduction stage 33 which, in turn, drives the reset mechanism gear 34 and the gear reduction stage 36. The reset mechanism gear 34 is on the same shaft and rotates with the clutch 16. The gear reduction stage 36 drives the gear reduction stage 37 which, in turn, drives the intermediate gear and pinion stage 38. The gear of the gear and pinion stage 38 drives the subinterval gear 49 which rotates the subinterval cams 50 and the pinion of the gear and pinion i stage 38 drives the time base unit gear 39. As the gear .39 rotates, the one-way clutch 40, shown as a pawl,

drives the ratchet wheel 42 which rotates the time base unit cam 26. When the solenoid 14 is energized, the pinion gear 35 is rotated with the gear 34 to drive the with the step-control gear 44. It can be seen that the stepcontrol cam 54 operates the contact members 17 and 21.

The time base unit cam 26 is rotated with the step-control gear 44 through the one-Way clutch 43, not shown in FIGURE 3.

FIGURE 3 also shows how the control cams 27 operate the contact members 52 which are connected to the terminal members 28.

Referring now to FIGURE 4, a side view of the timer of the present invention can be discussed.

The solenoid 14 is shown deenergized. When the clutch 16 is energized, the clutch arm 15 pulls the two parts of the clutch 16 together in opposition to the spring 16.

The time base unit cam 26, which is a drum type cam, has three distinct cam surfaces on its contour. The wire spring contact members 18, 19, 20, 22, 23, and 24 are operated by the three cam surfaces as the time base unit cam 26 rotates. The purpose and operation of the time base unit cam 26 will be discussed in an operational analysis of the present invention.

The axially moveable part 43' of the clutch 43 moves towards the time base unit cam 26 in opposition to the spring 53. The clutch part 43 is on a double-D shaft which fits into a double-D opening in the time base unit cam 26.

The motor 13 is removed from FIGURE 4 for clarity purposes.

Referring now to FIGURE 5 an illustration of the operation of the step-control cam 54 and the time base unit cam 26 can be discussed.

As the time base unit cam 26 is rotated in the direction of the arrow 55 by the gear 39, the step-control cam 54 is held in position as is shown in FIGURE 5. That is, the clutch 43 is overridden. The contact 21 is in the recess 54 of the step-control cam 54 and, therefore, is not in electrical contact with the contact 17.

It can be seen, in FIGURE 5, that the faces of the clutch 43 are together. The recesses 26', 26" and 26" are the three recesses in the time base unit cam 26 for operating the contacts 18, 19 and 20 shown in FIGURE 1. The recess 26' oeprates the contact 18, the recess 26" operates the contact 19, and the recess 26 operates the contact 20. Therefore, three diiferent time intervals can be established based on the rotation of the time base unit cam 26.

Referring now to FIGURE 6, the discussion of the operation of the step-control cam 54 and the time base unit cam 26 can continue.

As the time base unit cam 26 rotates through the angle X, the cntact 18 will fall into the recess 26' to make with the contact 22, thereby energizing the solenoid 14. The solenoid 14 is not shown in FIGURE 6.

The angle X is the angle through which the time base unit cam 26 must rotate from the starting point shown in FIGURE until the recess 26 is under the contact 18. The angle X, therefore, represents a predetermined time interval. At the time when the contact 18 drops to make with the contact 22, the step-control cam 54 will start to rotate with the gear 44 which is driven by the pinion gear 35. The pinion gear 35 is rotated when the clutch 16 is closed by the solenoid 14. It can be seen that the step-control cam 54 has to move through the angle designated in FIGURE 6 as less than X before the contact 21 will make with the contact 17. It can also be seen that the two faces of the clutch 43 have advanced an amount equal to the angle X. The face of the clutch 43 is represented by the dashed line which has advanced an angle X from the face that is shown.

Referring now to FIGURE 7, the discussion of the operation of the step-control cam 54 and the time base unit cam 26 can be continued.

The step-control cam 54 has been advanced in the direction of the arrow 57 to close the contacts 17 and 21. The contacts 17 and 21 keep the solenoid 14 energized after the contacts 18 and 22 are opened. It can be seen that the clutch 43 faces are engaged and that the time base unit cam 26 is being driven with the gear 44 and the step-control cam 54. The step-control cam 54 and the time base unit cam 26 will be driven to the starting position as shown in FIGURE 5.

With the above description of components in mind, and by making reference to the drawing figures, the following analysis of operation will serve to convey the functional details of the timer of the present invention. As stated previously, the timer of the present invention has both a rapid advance feature and a step-advance feature. The control elements for both of these features is the time base unit cam 26 and the step-control cam 54. The time base unit cam 26 is a means for determining the time interval between step-advances of the control cams of the timer. When the contacts which are associated with the step-control cam 54 are shorted together, the control cams of the timer will be driven through one or more cycles or to a preselected cycle at a high rate of speed.

Referring ow to FIGURE 2, it can be seen that when the clutch 16 is operated by the solenoid 14, the control earns 27 of the timer are driven from the motor pinion 32 through the reduction gear 33, reset mechanism gear 34, clutch 16, pinion gear 35, step-control gear 44 and step-control pinion gear 45, idler gear and pinion stage 46 and the camshaft gear 47. Also, when the clutch 16 is closed, the time base unit cam 26 is driven through the clutch 43 so as to rotate with the step-control gear 44. When the clutch 16 is not closed, the time base unit cam 26 is driven from the motor pinion 32 through the first reduction gear stage 33, second reduction gear stage 36, third reduction gear stage 37, intermediate gear and pinion 38, time-base unit gear 39, and the one-way clutch 40. When the clutch 16 is not closed, the time base unit cam 26 rotation will override the clutch 43.

The various time intervals for the step-advance feature of the timer are obtained by having a plurality of operating surfaces on the time base unit cam 26 for operating a pair of contact members. The illustrative embodiment of this specification shows the use of three different sets of contacts. Referring to FIGURE 1 it can be seen that the contact members 18 and 22, 19 and 23, and 20 and 24, all of which are molded in the terminal block 11, are operated by the rotation of the time base unit cam 26.

The time base unit cam 26 always rotates in the same direction. As the time base unit cam rotates through the three gear reduction stages 33, 36 and 37, the intermediate gear and pinion 38, the time base unit gear 39 and the one-way clutch 40, the selected recess in the cam will permit the contacts associated with said recess to close and to energize the solenoid 14.

By referring to FIGURES 5, 6 and 7, and assuming that the contacts 18 and 22 which are associated with the recess 26 are to determine the selected time interval, an understanding of the operation of the illustrative embodiment can be achieved. When the contacts 18 and 22 are closed, as is shown in FIGURE 6, the clutch 16 will be operated by the solenoid 14 to drive the time base unit cam 26 and the control cams of the timer until the solenoid is deenergized. Once the solenoid 14 is energized, the step-control cam 54 will be rotated with the stepcontrol gear 44 and the time base unit cam 26 to operate the contacts 17 and 21. The solenoid 14 is maintained in an energized mode through the contacts 17 and 21 after the contacts 18 and 22 are opened. Therefore, the solenoid 14 will continue to be energized until the step-control cam 54 is driven to the angular position where the recess 54' will permit the opening of the contacts 17 and 21. In this manner, the step-control cam 54 and the time base unit cam 26 are always reset to a zero position after a step-advance of the timer.

The various time intervals are determined by the location of the recesses in the time base unit cam 26 and the rotational speed of said cam. The angular amount that the control cams 27 of the timer is advanced is determined by the gear ratios of the step-control gear 44, pinion gear 45, idler gear and pinion stage 46, and the camshaft gear 47. The step-control cam 54 and the step-control gear 44 are always started in the same spot and stopped in the same spot. Hence, the amount of rotation of the control cams of the timer is always the same amount.

If the contacts 17 and 21 are externally shorted together the solenoid 14 will be energized to close the clutch 16 until the contacts 17 and 21 are opened. In this manner, a rapid advance feature is achieved. It will be noted that whenever the contacts 17 and 21 are shorted externally, the time base unit cam 26 and the stepcontrol cam 54 will be rotated until said contacts 17 and 21 are open circuited both externally and by the recess 54'. Hence, the step-control 54 cam will always stop at a position determined by the location of the recess 54.

The only driving means for the timer is the motor 13. Hence there is one motor for determining the time interval as well as supplying the rotational energy for rapidly advancing the timer. In the illustrative embodiment of the specification, a shaded pole motor is used.

The timer of the present invention, as hereinbefore described in one of its embodiments, is merely illustrative and not exhaustive in scope. Since many widely different embodiments of the invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interposed as illustrative and not in a limiting sense.

What is claimed is:

1. A timer comprising: a plurality of control cams mounted on a camshaft so as to be rotated thereby and a plurality of control switches operated by said control cams, a drive means; first cam means for determining a time interval for advancing said control cams, a plurality of contact members, said first cam means having a plurality of rise and fall contours for operating said plurality of contact members; second cam means for establishing the amount of advancement of said control cams, an associated pair of contact members, said second cam means having a contour for opening and clossing said associated pair of contact members as said cam means is rotated; means for coupling said first cam means to said driving means, said coupling means including a first one-way clutch; means for coupling said second cam means to said driving means when said first cam means has rotated a predetermined amount, said conpling means including a solenoid operated clutch; means for coupling said first cam means to said second cam means so as to advance said first cam means with said second cam means, said coupling means including a second one-way clutch; first circuit means for selectively connecting said contact members associated with said first cam means to said solenoid operated clutch, thereby energizing said clutch after a predetermined time interval; second circuit means for connecting said contact members associated with said second cam means to said solenoid operated clutch so as to deenergize said clutch after said control cams have advanced a predetermined amount; and means for coupling said second cam means to said camshaft so as to rotate said camshaft when said cam means rotated.

2. A timer as in claim 1 wherein said driving means is a shaded pole motor.

3. A timer as in claim 1 wherein there is a means for electrically shorting said contact members associated with said second cam means so as to rapidly advance said control cams of said timer to a particular cycle point.

4. A timer as in claim 1 wherein said first cam means and said second cam means are free to rotate in only one direction, said first cam means being free to rotate with respect to said second cam means.

5. A timer as in claim 1 wherein said means for coupling said second cam means to said camshaft is a spur gear means.

6. A timer as in claim 1 wherein said first cam means is a drum type cam having a plurality of distinct rise and fall contours formed thereon.

7. A timer as in claim 1 wherein there are a plurality of subinterval control cams driven directly by said driving means.

References Cited UNITED STATES PATENTS 3,033,999 5/1962 Thornbery et al. 307-l4.4 3,188,504 6/1965 Anderson 307-141.4 3,319,019 5/1967 Jullien-Davin 200-38 BERNARD A. GILHEANY, Primary Examiner.

H. E. SPRINGBORN, Assistant Examiner. 

1. A TIMER COMPRISING: A PLURALITY OF CONTROL CAMS MOUNTED ON A CAMSHAFT SO AS TO BE ROTATED THEREBY AND A PLURALITY OF CONTROL SWITCHES OPERATED BY SAID CONTROL CAMS, A DRIVE MEANS FIRST CAM MEANS FOR DETERMINING A TIME INTERVAL FOR ADVANCING SAID CONTROL CAMS, A PLURALITY OF CONTACT MEMBERS, SAID FIRST CAM MEANS HAVING A PLURALITY OF RISE AND FALL CONTOURS FOR OPERATING SAID PLURALITY OF CONTACT MEMBERS; SECOND CAM MEANS FOR ESTABLISHING THE AMOUNT OF ADVANCEMENT OF SAID CONTROL CAMS, AN ASSOCIATED PAIR OF CONTACT MEMBERS, SAID SECOND CAM MEANS HAVING A CONTOUR FOR OPENING AND CLOSSING SAID ASSOCIATED PAIR OF CONTACT MEMBERS AS SAID CAM MEANS IS ROTATED; MEANS FOR COUPLING SAID FIRST CAM MEANS TO SAID DRIVING MEANS, SAID COUPLING MEANS INCLUDING A FIRST ONE-WAY CLUTCH; MEANS FOR COUPLING SAID SECOND CAM MEANS TO SAID DRIVING MEANS WHEN SAID FIRST CAM MEANS HAS ROTATED A PREDETERMINED AMOUNT, SAID COUPLING MEANS INCLUDING A SOLENOID OPERATED CLUTCH; MEANS FOR COUPLING SAID FIRST CAM MEANS TO SAID SECOND CAM MEANS SO AS TO ADVANCE SAID FIRST CAM MEANS WITH SAID SECOND CAM MEANS, SAID COUPLING MEANS INCLUDING A SECOND ONE-WAY CLUTCH; FIRST CIRCUIT MEANS FOR SELECTIVELY CONNECTING SAID CONTACT MEMBERS ASSOCIATED WITH SAID FIRST CAM MEANS TO SAID SOLENOID OPERATED CLUTCH, THEREBY ENERGIZING SAID CLUTCH AFTER A PREDETERMINED TIME INTERVAL; SECOND CIRCUIT MEANS FOR CONNECTING SAID CONTACT MEMBERS ASSOCIATED WITH SAID SECOND CAM MEANS TO SAID SOLENOID OPERATED CLUTCH SO AS TO DEENERGIZE SAID CLUTCH AFTER SAID CONTROL CAMS HAVE ADVANCED A PREDETERMINED AMOUNT; AND MEANS FOR COUPLING SAID SECOND CAM MEANS TO SAID CAMSHAFT SO AS TO ROTATE SAID CAMSHAFT WHEN SAID CAM MEANS ROTATED. 